The present invention relates to floor care machinery and more particularly to an infinitely adjustable handle with a releasable clamp for floor care machines such that the operator may position the handle so as to optimize the operator""s control of the machine and ergonomic correctness.
Various types of floor care machines are currently available in the marketplace including machines that scrub, sweep, polish and/or burnish the floor surface. Such floor care machines typically include a base, an electric motor coupled to the base and a handle attached to the base for guiding and operating the floor care machine. Presently available floor care machines can provide for adjustment of the handle relative to the base. Many floor care machines are electrically powered, often requiring power cords. The handle designs of many of the floor care machines with associated electrical cords incorporate hooks for coiling the cord during periods of non-use.
One known handle adjustment mechanism provides a low-mounted cam-action lever, mounted directly to the base, which tightens a clamp that is otherwise free to slide on the handle. This mechanism allows for continuous adjustment of the handle relative to the base, but has a major disadvantage. The operator must either use a foot to actuate the clamp lever or bend over to reach the low-mounted lever by hand. Operating the lever by foot is acceptable when shifting the lever downward, but is ergonomically poor and difficult when shifting the actuator upward. The operation of the low-mounted lever by hand is ergonomically improper because the operator must exert force while bending or kneeling.
Another known handle adjustment mechanism provides a high-mounted handle release for a pawl and gear, or a pawl and notched plate. With this mechanism, the operator can select from a xe2x80x9cstoragexe2x80x9d position (typically vertical) and several xe2x80x9cworkingxe2x80x9d positions. The operator actuates a release lever to disengage the pawl from the gear or notched plate. Once the handle is positioned as desired, the operator releases the lever such that the handle settles into the nearest gear or notch. This adjustment mechanism can suffer from certain drawbacks. First, it is relatively expensive and complex to manufacture, thus generally relegated to expensive, feature-rich machines. Second, this mechanism limits the operator to a few specific handle positions. Unless the handle coincidentally falls into an ideal position, the operator is forced to work in an incorrect position. Third, this mechanism typically is subject to manufacturing tolerances and, hence, the handle position will have some xe2x80x9cplayxe2x80x9d or xe2x80x9cslop.xe2x80x9d This noticeable looseness in the handle position reduces the operator""s necessary precision in controlling the floor care machine, especially in low speed polishers where precise control can be crucial.
Yet another known handle adjustment design employs an expandable split ring mechanism on the interior tube of concentric, telescoping tubes to provide a releaseable friction clamp. While this design provides a high-mount handle and continuous adjustment, this split ring configuration appears to increase the cost of machine manufacture and assembly thereof. Moreover, the interior location of the clamping mechanism may make repair and maintenance challenging and time consuming.
In view of these perceived deficiencies in known floor care machines, it would be beneficial to provide an adjustable handle for a floor care machine in which the operator may conveniently and quickly adjust the handle to the desired location. It would also be advantageous to provide the operator of a floor care machine with a high-mounted lever to adjust the handle without placing himself or herself in an ergonomically undesirable position.
In accordance with the present invention, an adjustable handle assembly for floor care machines is disclosed. The adjustable handle assembly allows the operator of a floor care machine to conveniently adjust the handle unit of the machine relative to the floor working unit of the machine. Proper adjustment gives the operator optimal control over the floor working unit while working in a proper ergonomic position.
The floor machine of the present invention includes a floor working unit, a main handle assembly, and a handle adjustment assembly. The floor working unit performs the desired surface treatment, hence may include a scrubber pad or a burnishing disc. The main handle assembly is connected to the floor working unit and includes a gripping handle. The gripping handle is the means by which the operator grasps and controls the floor machine. The handle adjustment assembly includes an adjustment member and a locking assembly with an adjustment lever and a clamping mechanism. The operator of the floor machine may adjust the position of the main handle assembly by releasing the locking assembly, positioning the main handle assembly as desired, and securing the locking assembly. The release and securement of the locking assembly can be performed by moving the adjustment lever which actuates the clamping mechanism.
In another embodiment, the main handle assembly may include a main handle member. The main handle member may be a tube or a solid shaft. The adjustment member of the handle adjustment assembly is moveable relative to the main handle member. The handle adjustment assembly and the main handle member can be concentric tubes with the main handle member interior to the handle adjustment assembly.
The clamping mechanism of the handle adjustment assembly may include a first clamp block and a second clamp block, although a single, split block could be used. In the embodiment having two blocks, the clamp blocks are interconnected and attached to the handle adjustment assembly and are located exteriorly to the main handle member. The first clamp block may be moved toward or away from the second clamp block by moving the adjustment lever. The clamping mechanism may also contain an adjustment rod connected to the adjustment lever and the first and second clamp blocks. The adjustment rod can be pivotally connected to the adjustment lever and moveably connected to both the first clamp block and the second clamp block. The adjustment lever may incorporate a cam-type design on its contact surface with the first clamp block. The cam-type interface provides for the tensioning and release of the adjustment rod by positioning the adjustment lever along the cam surface.
The relative position of the main handle member to the handle adjustment assembly may be secured by pivoting the adjustment lever such that the first and second clamp blocks moved towards each other. The first and second clamp blocks frictionally grip the main handle member.
The handle adjustment assembly may also incorporate a lower block on the opposite end of the handle adjustment assembly from the first and second clamp blocks. The lower block may provide a mounting surface for two link arms. The link arms are attached to the lower block and may be pivotally connected to the main handle assembly or the floor working unit. Thus, the link arms maintain a spatial relationship between the lower block and either the main handle assembly or the floor working unit. The lower block may also incorporate a lower power cord wrapping member for storage of a power cord during periods of non-use. The power cord may be wrapped around the lower power cord wrapping member and the gripping handle. The main handle assembly may incorporate an upper power cord wrapping member. In this embodiment, the power cord is wrapped around the lower and upper power cord wrapping members, leaving the gripping handle unencumbered by the cord.
Based on the foregoing summary, a number of worthwhile aspects of the present invention can be readily identified. A floor machine is provided with a simple and convenient way of adjusting the handle of a floor machine relative to the base unit. The operator of the floor care machine may grasp and actuate the adjustable lever while holding the gripping handle. Since the adjustable lever is near the gripping handle, the operator need not place himself or herself in a physically compromising position to adjust the handle. The selection of an operating position is equally simple, since the operator need only to pivot the adjustment handle to secure the handle position. The simplicity of the design may reduce manufacturing costs such that the adjustable handle design of the present invention is available even on the less expensive models of floor care machines. Finally, the inherent design of the handle adjustment assembly is such that distance from the lower power cord wrapping member and the gripping handle, or the upper power cord wrapping member if so equipped, is greatest in the stored position. This allows the operator to quickly and easily remove the cord, without unwinding it, by simply lowering the handle from the storage position and placing the cord aside.
Additional advantages of the present invention will become readily apparent from the following discussion, particularly when taken together with the accompanying drawings.